Università Roma Tre

Aim: The Course provides the fundamentals of light and living organism interactions, focusing on the use of light for diagnosis and therapy. Photoproduction of energy (photosynthesis and its applications in green energy production), photophysical phenomena, light propagation in human tissues and use of light in the treatment of tumours and other pathologies are described in details. Biomedical applications related to photodiagnosis, photosensitivity, phototherapy, photodynamic therapy and photosensitizing drugs are examined. In addition, part of the course covers topics related to Optogenetics, a novel technique that uses light to control neurons, which have been genetically modified to express light-sensitive ion channels. Optogenetics uses a combination of optical and genetic techniques to control the activities of individual neurons in living tissues.

Topics

Fundamentals of light propagation in biological tissues
Interactions between light and molecules; electronic states of a molecule and the transitions between them: difference between bioluminescence, phosphorescence, fluorescence and other non-radiative phenomena; interactions between light, cell and tissues; effects of light propagation in biological tissues; fundamentals of the most employed light sources used in biomedical diagnostic devices.

Basics of biology
Cellular structure and types; chemical building blocks; cellular processes (central dogma of Biology): replication, transcription, translation, biosynthesis and energy production; protein classification and function; organization of cells in tissues; morphological and physiological description of the main tissue in human body.

Basic principles of genetic engineering and DNA manipulation
Polymerase chain reaction (PCR); restriction enzymes; cloning process. Genetic manipulation of microorganisms and superior organisms.

Biosensors
Principles; biorecognition; optical transduction; molecular basis of biosensors generation; bioluminescence, colorimetric, fluorescence and FRET-based sensors. Applications of biosensors in human oncology, bioremediation, food safety and drug production. Main devices and imaging techniques employed for biosensor detection.

Super-resolution imaging: techniques and biological applications
Physical principles and biomedical applications of different optical-super-resolution techniques (i.e., two and multi-photon microscopy, STORM, PALM, STED, expansion microscopy, rescan confocal microscopy, LLS, SIM). Physical principles and biomedical applications of different non-optical super-resolution techniques: electron microscopy (TEM, SEM, STEM); AFM.

Microarray Technology
Definitions and applications of Omic Sciences; typology of microarrays (DNA, protein, cell and tissue microarrays).

Photosynthesis
Plastids in plants; light and dark reactions; Calvin cycle and carbon fixation; ecological aspects on photosynthesis; natural and artificial photosynthesis for green energy generation.

Spectral tuning in Biology
Major pigments in biological systems; chemistry behind pigment photoefficiency (resonance theory, chemical environment and modifications in light absorption properties); chromatic acclimation and chromatic adaptation; molecular aspects of chromatic acclimation.

Visual tuning in humans
Human eye anatomy; human eye aberration: wave and chromatic aberrations, intraocular scattering; OCT; retina tissue organization; cytology of rod and cone cells; rhodopsin and retinal: structure and functions; retinal photocycle: molecular isomerization at the basis of vision; phototransduction cascade in vertebrate photoreceptors.
Optogenetics
General description of optogenetic molecular tools; opsins in animals; mechanisms of genetic construct delivery into mammalians; optrodes: applications and limitations.
Photophysiology and Phototoxicity
Vitamin D: photosynthesis and metabolism in human body; evolutionary aspects of vitamin D-mediated regulation of calcium homeostasis; human skin organization and differentiation of skin cell types; melanin production and functions; effects of ultraviolet radiation; effects of photodamaging on cells; mechanisms of DNA repair after photodamaging: homologous recombination, mismatch repair, Nucleotide Excision Repair, photolyase and UVR-mediated repair; photosensitivity diseases; light-dependent circadian cycle.

Fundamentals of the photothermal therapeutic effects of light sources
Interaction of light and physical sensing; phototherapy; photodynamic therapy; photosensitizing drugs.

Guided tour in the RomaTre Department of Sciences on the facilities and equipment studied in the course (luminometer, fluorimeter, flow-cytometer, devices for genetic manipulation).
Guided tour in the RomaTre Department of Sciences on confocal microscopes.
Guided tour in the LIME laboratories on the TEM, SEM and AFM microscopes.

Prasad PN. Introduction to Biophotonics 2nd edition. Wiley-Interscience, Hoboken, NJ. 2003;
Björn LO. Photobiology: The Science of Life and Light, 2nd edition. Springer-Verlag, New York. 2008.
Alberts B, Bray D, Hopkin K, Johnson AD, Johnson A, Lewis J, Raff M, Roberts K, Walter P. Essential Cell Biology. 3rd edition. Garland Science. 2010.